Cross-language Complex Parameter Interaction

Overview

This sample shows how to pass and call complex data types, including uint8Array, object, hashMap, pixelMap, and class, between ArkTS and C++.

Preview

App Home Page	Uint8Array	Object

HashMap	PixelMap	Class

How to Use

1. On the home page, there are five buttons corresponding to the following data types:
2. Uint8Array: Input a number ranging from 0 to 255 in each text box in the upper part. After you tap Execute, the program passes the array from ArkTS to C++, and then returns the array to the output box in the lower part.
3. Object: Input a proper value of Age and Name in the text box in the upper part. After you tap Execute, the program passes the object that contains the input information from ArkTS to C++. C++ determines whether the object is an adult, sorts the objects by group, and returns the object that contains the output information to the output box in the lower part.
4. HashMap: Input a number ranging from 0 to 9 in each text box in the upper part. After you tap Execute, the program passes the hashMap that contains the input information from ArkTS to C++. C++ accumulates the input values of each object and returns the hashMap that contains the output information to the output box in the lower part.
5. PixelMap: After you tap Execute, the program passes the pixelMap of the image from ArkTS to C++. C++ processes the image as a black-and-white image, returns the image to ArkTS, and then re-renders the image.
6. Class: After you tap ArkTS class pass to Napi, the program passes the ArkTS class to C++. C++ calls the method and returns the result to the output box. After you tap Napi class pass to ArkTS, the program passes the C++ class to ArkTS. ArkTS calls the method and returns the result to the output box.

How to Implement

1. Use the napi_define_properties and napi_define_class APIs to bind the functions and classes of ArkTS and C++.
2. Use uint8ArrayPassing function to pass uint8Array data. You can construct a buffer, use the napi_get_arraybuffer_info API to pass the array from ArkTS to C++, and then use the use napi_create_arraybuffer API to return the array.
3. Use objectPassing function to pass object data. You can use the napi_get_cb_info API to pass data from ArkTS to C++, and then use the napi_create_object_with_named_properties API to construct an object and return it.
4. Call the hashMapPassing function to pass hashMap data. This function serializes the hashMap and passes the result to C++ as a string. Then the nlohmann library is used to deserialize the hashMap in C++, edit it, and then serialize it again. Finally,the hashMap is returned to ArkTS as a string and JSON is used to deserialize the hashMap again.
5. Call the pixelMapPassing function to pass pixelMap data in the uint8Array format, which is almost the same as calling the uint8ArrayPassing function.
6. Call the classPassingTs2Napi function to pass class data from ArkTS to C++. You can obtain the property through the napi_get_named_property API and call the function through the napi_call_function API
7. Call new sampleClassNapi2Ts() to pass class data from C++ to ArkTS. You can query and set properties using getHintStr and setHintStr respectively, define a class using the napi_define_class API, and define a parameter using the napi_set_named_property API.
8. For details about the implementation, see napi_init.cpp.

Project Directory

 ├───entry/src/main/ets                             
 │   ├───entryability
 │   │   └───EntryAbility.ets                        // Ability lifecycle callbacks
 │   ├───entrybackupability
 │   │   └───EntryBackupAbility.ets                  // Backup ability lifecycle callbacks
 │   ├───model
 │   │   ├───IDModel.ets                             // Ad component parameters
 │   │   └───SampleObject.ets                        // Object type declaration
 │   └───pages
 │       ├───ClassPage.ets                           // Class passing page
 │       ├───HashMapPage.ets                         // HashMap passing page
 │       ├───Index.ets                               // Home page
 │       ├───ObjectPage.ets                          // Object passing page
 │       ├───PixelMapPage.ets                        // PixelMap passing page
 │       └───Uint8ArrayPage.ets                      // Uint8Array passing page
 ├───entry/src/main/cpp  
 │   ├───thirdparty                                  // Third-party library files
 │   ├───types/libentry/Index.d.ts                   // Functions and type declarations
 │   ├───CMakeLists.txt                              // Cmake compilation configuration file
 │   └───napi_init.cpp                               // C++ project
 └───entry/src/main/resources                        // Static resources

Dependencies

N/A

Constraints

1. The sample is only supported on Bar phone, Bi-fold phone(Mate X series) running the standard system.

2. The HarmonyOS version must be HarmonyOS 5.0.5 Release or later.

3. The DevEco Studio version must be DevEco Studio 5.0.5 Release or later.

4. The HarmonyOS SDK version must be HarmonyOS 5.0.5 Release SDK or later.